کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
751229 895212 2010 7 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Trace determination of molybdenum by anodic adsorptive stripping voltammetry using a multi-walled carbon nanotubes modified carbon paste electrode
موضوعات مرتبط
مهندسی و علوم پایه شیمی شیمی آنالیزی یا شیمی تجزیه
پیش نمایش صفحه اول مقاله
Trace determination of molybdenum by anodic adsorptive stripping voltammetry using a multi-walled carbon nanotubes modified carbon paste electrode
چکیده انگلیسی

A method for the voltammetric determination of trace molybdenum using a multi-walled carbon nanotubes modified carbon paste electrode (MWCNT/CPE) was described. The new procedure is based on the adsorptive accumulation of the Mo(VI)–alizarin violet (AV) complex onto the surface of the modified electrode, followed by the electrochemical oxidation of adsorbed species. The modified electrode showed high electrocatalytic activity toward the oxidation of the free ligand and the complex and the peak current was enhanced significantly. The optimal experimental conditions include the use of 0.12 mol L−1 potassium biphthalate (KHP) buffer (pH 3.6), 4.0 × 10−6 mol L−1 AV (cMo(VI) ≤ 1.0 × 10−7 mol L−1)/4.0 × 10−5 mol L−1AV (cMo(VI) > 1.0 × 10−7 mol L−1), an accumulation potential of −0.30 V (versus SCE), an accumulation time of 120 s, a scan rate of 100 mV s−1 and a second-order derivative linear scan mode. The oxidation peak for the complex appears at 0.59 V. The peak current increases linearly with Mo(VI) concentration in the range of 4.0 × 10−10 mol L−1 to 1.0 × 10−7 mol L−1 and 2.0 × 10−7 mol L−1 to 8.0 × 10−6 mol L−1 and the detection limit (S/N = 3) is 1.0 × 10−10 mol L−1 (accumulation time 120 s). The proposed method was applied to the determination of Mo(VI) in natural water samples with satisfactory results.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sensors and Actuators B: Chemical - Volume 148, Issue 1, 30 June 2010, Pages 214–220
نویسندگان
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